Fusion abrading process for surfaceworking flat and curved surfaces of metal bodies and apparatus for carrying out said process



June 14, 1960 w. OSENBERG 2,940,226

FUSION ABRADING PROCESS FOR SURFACE-WORKING FLAT AND CURVED SURFACES OFMETAL BODIES AND APPARATUS FOR CARRYING OUT SAID PROCESS Filed Oct. 24,1956 7 FIG 2 22 I 9 FIG 13 4 J V i i INVENTOR Werner Osenberg m zsa/ agA TFORNEYS Ute rates atent FUSION ABRADING PROJESS FOR SURFACE- WORKINGFLAT AND CURVE!) SURFACES OF NIETAL BGDES AND AfPARATUS FOR CARRY- lNGOUT SAID PROCESS Werner Osenberg, Gehrden, Germany, assignor toBisterfeld & Stolting, Radevormwald (Rheinland), Germany, a'firm FiledOct. 24, 1956, er. No. 618,131

Claims priority, application Germany Oct. 24, 1955 Claims. (Cl. 51-409)The present invention relates to a process and'apparatus for carryingout said process of working the flat and curved surfaces of metallicbodies by simultaneous thermal and'mechariical action by means of apower-driven tool rotating at a high speed within the range of a highenergy flow, having finely serrated friction edges and kept very narrowfor the purpose of concentrating energy.

The narrow finely serrated friction edges may be arranged at a certaindistance apart either on the periphery or concentrically on the sidewalls of the rotating fusion abrasive tool made from high-resistancesteel. In any case, in order to produce a high concentration of energy,not only a high friction edge speed and a strong drive are necessary,but also suitable bearing and feeding forces must'be applied so astoconvert into a pasty or liquid state, representing the characteristicof the fusion abrading process, the material to be removed from thesurface of the workpiece directly below the friction'edges, as a resultof the concentration of energy. At the same time the liquid material isflung aside or burnt by the teeth, gaps and roughness of the frictionedges under the action of-the oxygen of the air which is continuouslyfed to the points of contact by the adhesive effect of the frictionedges.

In view of the high energy fed per unit of'time, con- 'centrations ofheat occur in the vicinity of these contact points and on the one handincrease the abrading performance at the high peripheral and feed speedsand on the other hand prevent useless heat dispersioninto the Zonesadjacent these points, so that the structural spectrum in these zonescan only be afiected under most unfavorable circumstances in a thinlayer which can easily beremoved by subsequent or simultaneous grinding.

The principle of utilizing frictional heat for the purpose of removingmaterial has already been applied with success in connection withfriction parting discs and fusion band saws. In the case of both typesof tools the material becomes pasty or liquid in the incision and isalso carried off by fine teeth. it-has already been proposed to work thesurfaces of workpieces by means of narrow cutting edges impregnated withhard materials and arranged concentrically on the end face of a rotarytool, as

in the case of the subject matter of the invention. How- 'ever, thisapplies to a grinding process in which the granular hard materialembedded in the cutting edges cuts off chips of material. The processaccording to the invention, on the other hand, utilizes exclusively thefric tion heat producing a surface liquefaction at the working point.The fine teeth of the friction edges, which on becoming blunt can beresharpened at the same time by knurling tools, also remove theliquefied material.

Contrary to the friction parting saws serving for cutting material intolengths and the use of which moreover does not detrimentally affect thestructure adjacent the cutting point, the high-speed rotary toolaccording to the invention operates in most cases in several steps orstages 7 with the fusion abrading disc.

and as a result of the arrangement on the end face of one or more narrowedges enables surface-grinding to be carried out. To render it possibleto exert the axial hearing pressures which cause the great accumulationof 'heat constituting the primary condition for carrying out the fusionabrading process, the end face friction disc canbe supported in axialdirection not only by its spindle but inaddition by means of rollers,balls and the like on its periphery.

In order to further increase the amount of material removed by thefusion abrading process it can beconverted into an electro-frictionalprocess by introducing electric energy and producing arcs between theend friction disc and the workpiece, or it can be combined with agrinding process operating with loose grit. The grit either loose or inthe form of a paste can be introduced either by means of a gaseous orliquid pressure medium through nozzles between the serrated friction orabrading edges, which if necessary are profiled in transverse andlongitudinal direction, and the surface of the Workpiece, or loose gritis placed in a container closable on all sides and-in which the fusionabrading disc, coated by dipping or spraying with a thin elastic layerfor reasons of wear, runs and contacts the workpiece, for example arail, a tube or the like. The container is provided at both ends withpackings corresponding to the crossectional shape of the profile of, forexample, a rail. The workpiece to be Worked is pushed through thecontainer bya feeding device and can, if it is a question of a rotarybody such as a tube, carry out a circular feed movement at the sametime. Inversely the container with the rotary frictiondisc can also bemoved over the workpiece, which in this case is awstationary workpiece.

Known types of grinding tools can also be combined Thus it is possibleto arrange on the end face of the friction'disc concentric with theannular edges only to exert friction, for example two-stepped ringsimpregnated with abrasive with ceramic or plastic bond, which then exerta cutting effect inaddition to the friction effect.

Several embodiments of the invention are illustrated by way of examplein the accompanying drawing, in which Fig. 1 is a side elevation, partlyin section, showinga three-step orstage fusion abrading disc,constructedtas an end face disc with axial support by means of conicalrollers;

Fig. 2 shows a single-step fusion abrading disc in part side elevation;

Fig. 3 shows a four-step fusion abrading disc in part side elevation;

Fig. 4 is a part. side elevation of a fusion abrading disc composed of a.carrier disc with two.two-step friction abrading rings firmly securedon it;

Fig. 5 is a part side elevation of a fusion abrading disc composed of acarrier disc, a two-step friction ring and concentric thereto a secondtwo-step ring saturated with abrasive'grit;

vFig. 6a shows in part cross-section a two-stepzfusion abrading discwith knurling rolled therein;

Fig. 6b is a similar cross-section wherein the webs and their frictionedges are inclinedto their working plane;

.Fig. '7 is a part cross-sectionshowing a two-step fusion abrading'discwith rolled-in knurling rand recess in the friction edger spacers;

Fig. 10 shows in part cross-section a two-step fusion sarily be axiallyparallel. edges may also be inclined to the working or friction abradingdisc with inserted adjustable ring of plastic material;

Fig. 11 shows in bottom plan view a four-step fusion abrading discwherein loose abrasivegritis fed to the frietionizones by nozzles;

Fig. 12 is a side elevation of the four-step fusion abrading discillustrated in Fig. 11;

Fig. 13 shows the arrangement of a four-step fusion tainer' which can befilled with loose abrasive materials, and i V t Fig. 14 shows thearrangement of a four-step fusion abrading disc serving for working arailway rail, in a 'piece 9 by means of the abrading or friction discrotating at a highs'peedflhe complete friction disc is additionallysupported by means of conical rollers '(Fig. 1) which bear against theconical surfaces 6 and 8. Sis a hardened ground surface of the guidebody 7 which is keyed on the spindle 2 and at the same time bearsagainst the shiftable machine part 3 carrying the spindle 2. Asshown inFigs. 1 to 3, the webs 4 carrying the friction edges 13 can be made inone piece with the friction disc 1. They may,"howe ver, as shownin Figs.5 and 4, be inserted as two-stepped friction rings 11 and 12 in acarrier disc 10. The friction process can according to Fig. 5, also becombined with a grinding process. The carrier disc in this case carries,in addition'to the two-step friction 11, independently adjustable inaxial direction as regards its position in relation to the workpiece,also a two-step ceramic or plastic bond grinding ring. The fiiction ring11 in this embodiment of the invention, is fixed 'on the carrier ring10' which is'adjustable relatively to the carrier disc either before orduring the grinding operation by means such as those mentioned, forexample, in

the description of Fig. 10.

I Y As is usual in the case of friction parting discs, the friction edgecoming into contact with the workpiece is, as shown in' Figs 6a to 8,provided with a'knurling that is with fine toothing 13. The knurling isrolled into the annular webs 4 by a rotary knurling tool under heavypressure and can be re-rolled as the friction teeth become wom-or blunt-1 The arrangement of the annular webs 4 need not neces- The webs andtheir friction plane, as indicated at 4' in dotted lines in Fig. 6b. By

inclining the friction edges 13 and 14, the material of the liquid filmforming during the fusion abrading process can be carried oif moresatisfactorily by a feed movement. 7 1

Inthe case of the simultaneous use of loose abrasive grit, to enable thegrit to be carried along'in a reliable manner, the knurling can beformed as shown in Fig. 7 so that the friction edge 13 has a depression14. Further more, the annular webs 4, may, as illustrated in Fig. 8,

be' provided with gaps 7 28 and the friction edg'e'with undercutporti0ns'15 The arrow in Fig. 8 shows that the friction edge'is moved'ina direction which produces i would act not in axial direction to theface of the friction disc but in radial direction thereto. If severalwebs are provided, the peripheral toothing of the webs would abradingdisc serving for working tubes, in a closed cona' pinching eifect andtherefore conveys the loose abrasiveduring the movement of the frictionedges 1 3-over.

the surface of the workpiece; The fine teeth of the fric-' tion edgesare shown only on the end face of the individual webs in the figures ofthe drawing, but may also 7 veyor worm.

with suitable feed movement, enable a multi-stage abrasron.

The construction of the fusion abrading toolmay also .be as shown inFig. 9, wherein several friction discs 40 are arranged parallel to eachother on a strong shaft 2 and held at suitable distances apart byspacing members 27. By making the friction discs 49 of differentdiameters the complete friction tool :will be of hyperboloidal shape, sothat, for example, when working railway rails, a cambered shape can beproduced on the rolling surface of the rail by inclining the wholepower-driven tool relatively to the central axis N of the rail, as shownin Fig. 9.

Whenloose abrasive grit is-used at the same time, the carrying along ofthis grit can also be eflected as shown in Fig. 10 by embedding a ring-16 of plastic material in the groove-shaped cavity between the frictionedges 13 and 14, which ring can be pushed into the groove by hydraulicmeans. For this purpose a steel ring 17 is placed in the groove and canbe hydraulically shifted by means of pistons 18 in the directionoftheworking edges 13, 14 of the friction tool. The pressure medium foractuating the pistons 18 can be introduced through the bore 19. Thecontrol pressure cylinder for the pressure medium is arranged centrallywithin the center axis of the friction tool so that the oil pressure canbe varied even while the tool is rotating and the ring 16 of-plasticmaterial pushed towards the working edges thereof. Thus it is possiblefor the ring 16 to project beyond the friction edges by a distance H, asshown in Fig. 10. Owing tothe plasticityof the ring 16, the loose,abrasive grit is continuously fedback to the friction points in themanner necessary when the fusion abrading disc isarranged as shown inFigs; 13 and 14. I

The loose abrasivegrit can also be forced through nozzles 20 to 20""between the friction edges 4 and the surface of the workpiece 9, bymeans of gaseous or liquid pressure media such as oxygen, etc. It isadvisable to arrange the pressure nozzles 20' to 20" tangentially to thefriction rings. For the'sake of clearness, thepressure'nozzle 20 isshown turned in the plane of the drawing in Fig. 12. a

The containers 21 of Figs. 13 and 14 can be closed by covers 22 and 23.The whole container is filled with granular abrasive which can evidentlyalso be embedded in a carrier mass. To prevent'the loose abrasive fromfalling out of the container during the grinding process, the containeris, according to Fig. 13, sealed in relation to the piece to be worked,in this case a rail, by means of plastic pressure members 24. Ascan beseen from Fig. 14, this seal can be attained by inflating the packing ofplastic material by the application of pressure, for which purpose thepacking 24 is provided with hollow spaces 25. If a tubular body 9 is tobe surface-ground as shown in Fig. 14, a slow turning movement in thedirection of the arrow and a longitudinal feed movement can be impartedto it, so that it is possible with a rigid housing 21 and stationaryfriction disc spindle Zto work the surface of the tube on the one handby applying the friction abrading process and'in addition by a grindingprocess with simultaneous feed of 'loose abrasive. When introducing afresh tube into the container 21, a dummy length 26 is introduced aheadof the front end of the tube so that the beginning of the tube is alsocleanly surface-worked.

The loose abrasive grit can, accordingto Figs. 13 and 14, be removedfrem the container periodically and freed from metallic impurities. Itis evident that a continuous process might be introduced for thispurpose and the abrasive grit led off from the container by means of a'con- It can-then be magnetically freed from metallic impurities andreturned into the container from above after it hasbeen cleaned. V, p

As shown in 'Figgl4, it is advisable to incline the'central axis of thefusion abrading disc relatively to the surface of the workpiece. Thefriction edges 4 must then be likewise correspondingly conicallybevelled.

In order to protect the friction tool rotating in the abrasive againstwear in the constructions illustrated in Figs. 13 and 14, it isadvisable to provide the whole metal tool with a coating of elasticmaterial at regular intervals. This coating can be produced by dippingor spraying. At the commencement of the abrading process, the frictionedges of the tool immediately become exposed, so that the coating isthen only present on the portions of the tool which are not in contact.The arrangement of the fusion abrading tool and its spindle can,especially when loose abrasive is introduced at the same time, also besuch that the spindle stands upright and the end friction disc isarranged over it in such a manner that the loose adhesive fills the gapsbetween the concentrically arranged webs under the effect of gravity andis carried along as the friction disc rotates. It is evident that inthis application of the process, wherein the workpiece is located belowthe friction disc, a closed container, as shown in Figs. 13 and 14, isnecessary.

If the friction disc is electrically insulated from the workpiece,electric arcs can be produced between the friction edges and the surfaceof the workpiece by feeding electric energy, thereby supplementing theheat concentrations and assisting the liquefaction of the surface of thematerial resulting in an increase in the abrasive performance.

The multi-step or stage friction rings 11 and 12 mounted in a carrierdisc according to Fig. 4 can also be built up from multi-step segments,should the production of closed friction rings prove too expensive.These multistep segments, which may be produced by forging or pressing,are then fitted together in such a manner that continuous circularfriction edges are formed.

It is evident that the process according to the invention can be carriedout in many ways. Attention is directed to the fact that in thespecification only a few solutions of the problem can be given by way ofexample. The workpieces shown in Figs. 13 and 14 can also be of variousshapes. Obviously instead of rails and tubes, also flat materials,sheets, bands, rods, wires and the like, can be worked with the aid ofthe fusion abrading process.

The process, may, as already mentioned in the description of Fig. 5, besimultaneously combined with a grinding process. This combination isrendered possible in that, when grinding relatively long workpieces,these are first roughly worked by a fusion abrading disc andsubsequently fine worked in the same operation by a multiple-stephighspeed grinding disc arranged beside the friction disc and broughtinto contact with the workpiece to remove the ridges produced by thefriction process.

I claim:

1. Fusion abrading process for working flat and curved surfaces of metalbodies, comprising pressing on to the surface of the workpiece at leastone finely serrated edge of a power-driven tool rotating with circularmotion at a high speed within the range of a high specific surfacepressure, said edge being narrow for the purpose of concentratingenergy, and at the same time imparting a high feed movement at rightangles to this bearing pressure.

2. Fusion abrading process as set forth in claim 1, comprisingadditionally producing electric arcs in the range of the high specificsurface pressure by direct feed of electric energy for the purpose ofincreasing the concentration of heat.

3. Fusion abrading process as set forth in claim 1, comprisingadditionally feeding abrasive material into the range of the high energyflow for the purpose of increasing the mechanical abrasive performance.

4. Fusion abrading tool for working flat and curved surfaces of metalbodies, comprising at least one finely serrated narrow friction edgeforming the end face of annular webs extending coaxially at a distanceapart fi'om the end face of a friction tool made of high-resistancesteel.

5. Fusion abrading tool as set forth in claim 4, wherein the finelyserrated friction edges are also provided on a portion of the side Wallsof the webs.

6. Fusion abrading tool as set forth in claim 4, wherein the finelyserrated friction edges are at an incline to the axis of the tool.

7. Fusion abrading tool as set forth in claim 4, wherein the frictiondisc made from high-resistance steel is additionally equipped withrolling bearing on its periphery for taking up the bearing and feedingforces acting in axial direction.

8. Fusion abrading tool as set forth in claim 4, wherein the serrationof the friction edges of the annular ribs are provided with recessesboth in transverse and longitudinal direction for additionally feedingloose abrasive to the contact points by pinching effect.

9. Fusion abrading tool as set forth in claim 4, wherein wear-resistingelastic rings adjustable and'readjustable in axial direction are fittedin gaps between the webs and friction edges and serve for additionallyfeeding loose abrasive material.

10. Fusion abrading tool as set forth in claim 4, wherein the tool andthe workpiece are enclosed on all sides in a container filled withabrasive material into which container the workpiece is pushed duringthe working operation.

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